Internal-combustion engine



July 9, 1929. 1 1.720.261

INTERNAL COMBUSTION ENGINE Filed June 18, 1925 2 Sheets-Sheet l //YVE/V ro/e/ JVEI 6' 7722?. .2904? r/vs 77-. g? A 7).

y 9, 1929- E. R. BURTNETT 1.720.261

INTERNAL COMBUSTION ENGINE Filed June 18, 1925 2 Sheets-Sheet 2 27 5/65 7' rf. Bale 7N5 7- 7-.

Patented July 9, 1929.

UNITED STATES PATENT OFFICE.

EVERETT R. BURTNETT, OF LOS ANGELIES, CALIFORNIA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE AUTOMOTIVE VALVES 00., LOS ANGELES, CALI-' FORNIA, A VOLUNTARY TRUST.

INTERNAL-COMBUSTION ENGINE.

Application filed June 18, 1925.

My invention relates to a multi-cylinder internal combustion engine that operates on the two stroke cycle principle, and the principal object of my invention is to provide a twelve cylinder engine wherein the cylinders are arranged in two rows of six cylinders each, said rows being disposed so as to form a V-block, the wings of which are arranged 90 apart and in which a constant reciprocatory mass inertia is developed at each crank pin so that complete rotary and reciprocating balance can be obtained by the use of a rotary counterweight part of the crank shaft that is equal to the total reciprocatory inertia weight developed at each crank pin and the crank pin end arms.

I accomplish this result by providing a twin six engine with a three throw crank shaft and attaching four pistons to each crank thereof. As a result of this arrangement, the two pistons at either end of both rows of six cylinders are connected to one of the three cranks of the crank shaft, the two pistons of the third and fourth cylinders from either end of the two rows are connected to the second or center crank pin and the two pistons within the two cylinders at the remaining end of each row of cylinders are connected to the third or other end crank pin of the crank shaft. As a result of this arrangement, the reciprocatory force can be canceled out in the plane in which it is developed, thus eliminating the development of reciprocating out-of-balance forces'to be countered from one plane to another and such result being possible due to the spacing of the two rows of six cylinders in the V-structure 90 apart.

The structure herein disclosed is an improvement upon the six cylinders in a row arrangement disclosed in my co-pending application now Patent No. 1,697,553, Jan. 1, 1929.

\Vith the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawing in which Fig. 1 is a vertical section taken lengthwise through the center of one of the wings of my improved engine.

Fig. 2 is a cross section taken approximately on the line 22 of Fig. 1.

Serial No. 37,991.

Fig. 3 is a cross section taken approximately on the line 3-3 of Fig. 1.

Fig. 4 is a cross section taken approximately on the line 44 of Fig. 1.

Fig. 5 is a cross section taken approximately on the line 55 of Fig. 1. Referring by numerals to the accompanymg drawing which illustrates a practical embodiment of my invention, 10 and 11 desig-' nate cylinder blocks that occupy planes 90 apart and associated with the lower ends of said blocks is a crank case 12 having four main bearings 13 for a crank shaft 14. This crank shaft has three crank throws and the pins 15, 16 and 17 of said three cranks are disposed 120 apart. Each crank pin has two finished bearing peripheries and arranged between each pair of peripheries and centrally upon each pin is an arm such as 18 that projects diametrically across the axis of crank shaft 14 and carried by the free end of each arm is a counterweight such as 19.

Each of the two wings of the V-block is provided with six cylinders the same being arranged to form three pairs and each pair comprises a bore or chamber of straight diameter and a bore or chamber having two diameters.

As illustrated in Fig. 1, the pair of cylinders at one end of the wing includes a straight diameter bore combustion chamber 20 and a two diameter chamber that includes a combustion chamber 21 and a pumping chamber 22. The chambers 21 and 22 are co-axial with the smaller chamber 21 arranged in the head or outer portion of the cylinder block. At the opposite end of the wing the pair of chambers includes a straight diameter bore combustion chamber 23 and co-axial chambers 24 and 25 of different diameters with the chamber of smaller diameter 24 disposed at the outerlor head end of the block.

Formed in the wing between the pairs of chambers just described is a straightdiameter bore chamber 26 and co-axial chambers 27 and 28 of different diameters and with the chamber of smaller diameter 27 being disposed adjacent to the head or outer end of the block.

The axes of the three chambers 20, 26 and 23 and of the three co-axial chambers 21, 22, 27., 28 and 24, 25, are parallel and in the same plane, and said axes intersect the axis of crank shaft 14. Thus the two sets of six cylinders each are arranged in two straight rows with the axes of the chambers in each row parallel and with the axes of the twelve cylinders intersecting the axis of the crank shaft.

Secured on the head end of one wing is head block such as 29 and formed in the underside of each block are three shallow chambers 30, 31 and 32. Chamber 30 connects and functions as a common compression and combustion clearance space for the head ends of the combustion chambers 20 and 21 and in like manner chamber 31 connects and functions as a common compression and combustion clearance chamber for .the head ends of combustion chambers 26 and 27. Chamber 32 connects and functions as a common compression and combustion' clearance chamber for combustion chambers 23 and 24.

Block 11 is fitted with a head block 29 that is identical in construction with block 29 just described.

The pumping chambers 22, 25 and 28 in both blocks are provided at their upper ends with charge volume inlet ports such as 33 and with pumped charge volume outlet ports such as 34 from which lead suitably arranged transfer ducts 35. The combustion chambers 21, 24 and 27 in both blocks are provided near their lower ends with charge volume inlet ports such as '36 and leading from the combustion chambers 20, 23 and 26 in both chambers of both blocks are twosdiameter pistons such as 40. The pistons within the pair of combustion chambers 20 and the adjacent pair of two-diameter chambers 21, 22,

i in both wings of the V-block are connected to pin 15 of the crank shaft by suitable connecting rods 41 and thus the pistons within the four cylinders at one end of the engine are connected to the same crank pin.

In like manner the four pistons in the straight diameter combustion chambers 23 and in the two-diameter chambers 24, 25, at the other end of the V-block are connected to crank pin17 by connecting rods such as 42. The four pistons in the pair of straight diameter combustion chambers 26 and the pair of two-diameter chambers 27, 28, are connected to crank pin 16 by suitable con necting rods such as 43.

Thus it will be seen that I have provided an engine wherein the cylinder block is of V-structure, the wings thereof being disposed apart with each wing containing six cylinders that are arranged in three pairs and each pair comprising a chamber of straight diameter and a chamber of two diameters.

A single crank shaft is provided having three crank pins arranged 120 apart and with four pistons, two from each wing, connected to each crank pin, and further that each crank pin is counterbalanced by a weight carried at the free end of diametrically arranged arms. As a result of this arrangement a constant reciprocatory mass inertia is developed at each crank pin while the engine is in operation and complete rotary and reciprocatory balance is obtained, thereby wholly eliminating the development of reciprocating out-of-balance forces and consequent vibration.

It will be understood that during operation of my improved engine a charge volume that is pumped from one of the pumping chambers enters the inlet port such as 36 to one of the combustion chambers of each two-diameter cylinder at the time that the piston therein is at low center and this charge volume in passing through the connected combustion chambers drives out through the corresponding exhaust ports 37 the greater portion of the burnt gases resulting from the previously ignited charge. As the pistons in the chambers into which the charge volume is admitted move upwardly in their respective chambers the charge volume is compressed in the upper portions of said chambers and the clearance chamber connecting same, and as the pistons pass high center the compressed charge is ignited by a spark produced between the terminals of the corresponding spark plug and the rise in pressure following combustion of the compressed charge acts directly upon the heads of the pistons to drive the same clownward on their power stroke.

Inasmuch as the engine comprises six power units connected to the three crank pins of the crank shaft, the latter will receive six power impulses to each revolution and this will result in an even flow of power during engine operation.

It will be understood that minor changes in the size, form and construction of the various parts of my improvedengine may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which is set forth in the appended claim.

I claim as my invention: 1

In a two stroke cycle internal combustion engine, twelve cylinders arranged in two rows of 51X cyhnders each, the six cylinders in each row being arranged 1n three pairs,

each pair of cylinders comprising a cylinder having a straight diameter and a cylinder having a two diameter chamber, the larger portion of each two diameter chamber being provided on one side at its upper end with an inlet port and on the other side at its upper end with an outlet port, the smaller portion of each two diameter cylinder being provided near its lower end with an inlet port, the two rows of cylinders occupying angular planes ninety degrees apart, the six cylinders in one row being arranged in direct transverse alignment with the six cylinders in the other row, the heads of the members forming each pair of cylinders being connected by a common compression and combustion clearance chamber, a crank shaft journaled for operation and arranged so that its axis is intersected by the axes of the twelve cylinders, said crank shaft having three crank pins spaced one hundred twenty degrees apart, pistons arranged for operation within the twelve cylinders, the lower ends of the pistons in the two diameter piston chambers being provided with enlarged portions that cover and close the inlet and outlet ports in the enlarged portions of the two diameter chambers when the two diameter pistons are at the outer ends of their travel and connections from four of the pistons, two in each of the two rows of pistons, to each crank pin.

In testimony whereof I afiix my signature.

EVERETT R. BURTNETT. 

